Recent advances and prospects of inkjet printing in heterogeneous catalysis

This review provides an insight into inkjet printing technology in the context of heterogeneous catalysis.

Influence of the solvent type on the morphology and mechanical properties of electrospun PLLA yarns

An electrospinning technique based on the use of two oppositely charged nozzles was applied to fabricate continuous twisted yarns of poly(L-lactide) (PLLA) nano/micro fibers. In this study, the effect of solvent on the electrospinning of PLLA fibrous yarns was investigated. For this purpose, yarns were electrospun using chloroform, dichloromethane or 2,2,2-trifluoroethanol as solvents at a PLLA concentration of 7 wt%. The analysis of the morphology, diameter, crystallinity and mechanical properties of electrospun yarns revealed that the vapor pressure of the solvent plays an important role. Whereas the fiber diameter decreased, the crystallinity of the fibers increased using a solvent with lower vapor pressure. In addition, mechanical properties (e.g., tensile strength and modulus) revealed that the yarns composed of fibers with smaller diameters showed higher tensile strength and modulus. In summary, fine-tuning solvent properties resulted in a modulation of fiber diameter, crystallinity, and thereby yarn mechanical properties, and are important factors to consider in the fabrication and application of electrospun yarns.

Production of Heart Valves from Glassy Polymeric Carbon

When certain resins are pyrolized they transform into a glassy polymeric carbon (GPC) with no change in shape. Using this process we have made all-carbon heart valves by rapid molding of the component pieces out of precursor resin, assemblage in the resin stage and pyrolysis to at least 1,000°C to form an accurately articulated device. A heart valve with two occluders set in a carbon ring manufactured out of highly polished carbon has been tested with an excellent record of wear, fatigue, resistance and biocompatibility, especially in contact with blood.

A Carbon Drug Delivery System for Lithium

Lithium was introduced into pyrolyzed phenolic resins by dissolving lithium nitrate (5, 10, and 15% by mass) in a resol precursor. Impregnated specimens were pyrolyzed at 500°C, 575°C, and 650°C in inert atmosphere. After pyrolysis, samples were placed in 5 ml of phosphate buffered saline solution, refrigerated at 5°C, for various Li release times. Inductively coupled plasmaatomic spectroscopy was used to analyze these solutions, which were tested every 24 hours for 5 days; another set was tested after 60 days. Samples containing 5% lithium salt, fired to 500°C, released Li+at a lower rate than those fired at higher temperature. At the early stages of exposure to saline, samples fired at 575°C and 650°C released Li+at a higher rate, which fell to that of 500°C samples after many days. After leaching, nuclear reaction analysis using alpha radiation, with an exposure time of I hour, allowed us to analyze [Li+] and gradient up to 121μm below the surface. This indicates that a smaller [Li+] remains in 650°C samples than in those fired at 575°C and 500°C. For 500°C samples, [Li+] near the surface was lower than that for samples fired at 575°C and 650°C. This indicates that 500°C samples release Li+from near the surface, whereas samples fired at higher temperature release Li+from deep below the surface, probably because of higher permeability. Li+release rates of samples fired at 500°C and below 650°C follow a simple diffusion law, with diffusivities between 1017and 10-18m2/s. Li+rate may controlled over long time by a multilayered sprayed precursor with variable concentration.

Subclinical eating disorder, polycystic ovary syndrome- is there any connection between these two conditions through leptin- a twin study

The genetic property of subclinical eating behaviour (SEB) and the link between SEB and polycystic ovary syndrome (PCOS) has been studied before but the role of leptin within this connection has never been investigated. The objective of this study was 1). to study the genetic property of SEB. 2). To find a link between leptin, SEB and PCOS. One hundred and fifty four (77 pairs) female-female Iranian twins including 96 MZ individuals (48 pairs) and 58 DZ individuals (29 pairs) participated in the study. Clinical, biochemical and ultrasound tools were used to diagnose polycystic ovary syndrome. BITE questionnaire was filled out for subjects. Eight percent of subjects were diagnosed for subclinical eating disorder. No significant difference was found between intraclass correlation of MZ and DZ (z = 0.57, P = 0.569). Serum leptin level correlated significantly with bulimia score (P < 0.007). The mean (+/-SD) value for bulimia score was found to be higher among PCOS(positive) subjects (3.27 +/- 5.51) in comparison with PCOS(negative) subjects (2.06 +/- 4.48) (P < 0.001). The genetic property of subclinical eating disorder was not confirmed as shared environment might have played a major role in likeliness of DZ twins as well as MZ. Leptin is linked with both subclinical eating disorder and PCOS.

Leptin and its association with polycystic ovary syndrome: a twin study

Polycystic ovary syndrome (PCOS) is a common endocrinopathy with symptoms such as obesity, insulin resistance and hyperandrogenemia. PCOS might be the result of a genetic disorder. Genetic discrepancy in the production of leptin, a product of the obesity gene, may lead to various endocrinopathies such as PCOS. The objective of this study was first, to ascertain the incidence of PCOS, using the gold standard; second, to ascertain the genetic property of leptin; and third, to evaluate the association between leptin concentration and PCOS. A total of 154 Tehran-resident female-female twins were studied. They included 48 pairs of monozygotic (MZ) and 29 pairs of dyzygotic (DZ) twins, aged 15-45 years. Clinical, ultrasound and biochemical findings were used to diagnose PCOS. The incidence of PCOS using biochemical and clinical features was 16.2%. The correlation coefficient between serum leptin levels of MZ twins was higher than that of the DZ twins. The serum level of leptin was similar between subjects with or without PCOS, irrespective of their zygosity. It was concluded that the incidence of PCOS is high among twins, and that leptin is likely to be genetically determined, although the effect of environmental factors cannot be denied. This study did not find any association between the diagnosis of PCOS and leptin level. However, the link between the two may lie with other entities such as eating disorders and/or obesity.

Expressed emotion and the course of schizophrenia in Iran

BACKGROUND

The influence of expressed emotion (EE) on the course of the schizophrenia has been studied in different countries. Cultural influence on the level of EE has shown the importance of examination of EE in different cultures. The present study examined the distribution of components of EE and influence of EE on the course of schizophrenia in Iran.

METHODS

Two psychiatric centers from two dissimilar cities, Tehran and Hamedan, were chosen. Seventy-eight patients who suffered from schizophrenia based on the diagnostic criteria of DSM-III-R were selected. Interviews with 97 key family members were conducted using the Camberwell Family Interview. Psychiatrists who were blind to the EE status of the family household evaluated patients' symptoms based on a cohort study design during the 9-months follow-up.

RESULTS

Sixty percent of the patients were living in a high EE household. The relapse rate in the high EE group was higher, but did not reach statistical significance. However, male patients as well as chronic patients were significantly more likely to relapse in the high EE group (P = 0.05).

CONCLUSIONS

The results suggested that high EE is a risk factor on the course of schizophrenia in Iran. The distribution of the components of EE showed differences compared to other cross-cultural studies. The results of this study can be used in planning appropriate psychoeducational programs for families of patients in Iran and culturally similar populations.

Twenty-two cases of autotransfusion

Twenty cases of ruptured ectopic pregnancy and two cases of haemothorax which have been given autotransfusion by a simple technique are reported. No deaths or complications occurred. The advantages of autotransfusion particularly in circumstances where laboratory facilities are minimal are discussed. Haemoglobin levels before and after transfusion and other investigations are recorded.